/*
 * Copyright 2002-2012 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.jdbc.object;

import org.springframework.jdbc.core.PreparedStatementCreator;
import org.springframework.jdbc.core.PreparedStatementCreatorFactory;
import org.springframework.jdbc.core.PreparedStatementSetter;
import org.springframework.jdbc.core.namedparam.NamedParameterUtils;
import org.springframework.jdbc.core.namedparam.ParsedSql;

/**
 * Operation object representing a SQL-based operation such as a query or update,
 * as opposed to a stored procedure.
 *
 * <p>Configures a {@link org.springframework.jdbc.core.PreparedStatementCreatorFactory}
 * based on the declared parameters.
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 */
public abstract class SqlOperation extends RdbmsOperation {

    /**
     * Object enabling us to create PreparedStatementCreators efficiently,
     * based on this class's declared parameters.
     */
    private PreparedStatementCreatorFactory preparedStatementFactory;

    /**
     * Parsed representation of the SQL statement
     */
    private ParsedSql cachedSql;

    /**
     * Monitor for locking the cached representation of the parsed SQL statement
     */
    private final Object parsedSqlMonitor = new Object();


    /**
     * Overridden method to configure the PreparedStatementCreatorFactory
     * based on our declared parameters.
     */
    @Override
    protected final void compileInternal() {
        this.preparedStatementFactory = new PreparedStatementCreatorFactory(getSql(), getDeclaredParameters());
        this.preparedStatementFactory.setResultSetType(getResultSetType());
        this.preparedStatementFactory.setUpdatableResults(isUpdatableResults());
        this.preparedStatementFactory.setReturnGeneratedKeys(isReturnGeneratedKeys());
        if (getGeneratedKeysColumnNames() != null) {
            this.preparedStatementFactory.setGeneratedKeysColumnNames(getGeneratedKeysColumnNames());
        }
        this.preparedStatementFactory.setNativeJdbcExtractor(getJdbcTemplate().getNativeJdbcExtractor());

        onCompileInternal();
    }

    /**
     * Hook method that subclasses may override to post-process compilation.
     * This implementation does nothing.
     *
     * @see #compileInternal
     */
    protected void onCompileInternal() {
    }

    /**
     * Obtain a parsed representation of this operation's SQL statement.
     * <p>Typically used for named parameter parsing.
     */
    protected ParsedSql getParsedSql() {
        synchronized (this.parsedSqlMonitor) {
            if (this.cachedSql == null) {
                this.cachedSql = NamedParameterUtils.parseSqlStatement(getSql());
            }
            return this.cachedSql;
        }
    }


    /**
     * Return a PreparedStatementSetter to perform an operation
     * with the given parameters.
     *
     * @param params the parameter array (may be {@code null})
     */
    protected final PreparedStatementSetter newPreparedStatementSetter(Object[] params) {
        return this.preparedStatementFactory.newPreparedStatementSetter(params);
    }

    /**
     * Return a PreparedStatementCreator to perform an operation
     * with the given parameters.
     *
     * @param params the parameter array (may be {@code null})
     */
    protected final PreparedStatementCreator newPreparedStatementCreator(Object[] params) {
        return this.preparedStatementFactory.newPreparedStatementCreator(params);
    }

    /**
     * Return a PreparedStatementCreator to perform an operation
     * with the given parameters.
     *
     * @param sqlToUse the actual SQL statement to use (if different from
     *                 the factory's, for example because of named parameter expanding)
     * @param params   the parameter array (may be {@code null})
     */
    protected final PreparedStatementCreator newPreparedStatementCreator(String sqlToUse, Object[] params) {
        return this.preparedStatementFactory.newPreparedStatementCreator(sqlToUse, params);
    }

}
